Conventionally, a detection apparatus is known which takes the Fourier transform of received data with a plurality of noise signals and compares peak intensities in a resultant spectrum with a predetermined threshold so as to detect noise signals severally.
Literatures related to the aforementioned conventional technology include, for example, Japanese Laid-Open Patent Publication No. 2009-206603.
However, in the aforementioned conventional technology, there are still extra matters to further improve in view of accurately detecting the noise signals. For example, with the aforementioned conventional technology, it is hard to determine an appropriate threshold when a difference of the peak intensities between noise signals and other signals in the spectrum is minute, which is prone to a degradation of the accuracy of noise signal detection. The problem similarly arises in detecting various signals not limited to the noise signals.